1. Continued studies of mutant mouse which stores cystine in lysosomes as do cystinotic patients; anamolies in cholesterol metabolism uncovered similar to: a. Niemann-Pick C cells which show lysosomal storage of cholesterol and lack of intracellular cholesterol esterification. b. Niemann-Pick D cells which do not store cholesterol but do show a lack of cholesterol esterification. 2. Studies of cholesterol metabolism and transport in Niemann-Pick C and D fibroblasts. 3. Characterization of cystinotic cell metallothionein present in a 2-fold excess in cystinotic versus normal fibroblasts. 4. Investigation of metabolism of ascorbic acid in cystinotic fibroblasts.